Looking for info about an old sci-fi tv show?

Sometime in the 80s, maybe early 90s, I saw part of an episode of a sci fi show, and for years I've tried to find out what it was. All I remember is that it was set on a ship or space station, and the crew were visited by aliens. I have the feeling this was a regular thing and it may have been some sort of diplomatic event. The aliens in this instance looked human, they wore black leather or vinyl or something similar, they had hair like Alice Cooper, and they wore sunglasses with three lenses. When they took the glasses off, it was revealed they had a third eye, which they could use to paralyse a person. They first used it on, I think, the chief of security (who I think may have been a jackass, so it was funny), and they stole his watch.
At the end, they tried to use it on the captain, but he ducked and the aliens froze themselves.

I've looked at lists of sci fi shows from the 60s, 70s, 80s, 90s, I can't find it. Maybe it was a one off as part of something else? I don't know. Any ideas?

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